Biopolar electrosurgical instruments apply radiofrequency (RF) energy to a surgical site to cut, ablate, or coagulate tissue. A particular application of these electrosurgical effects is to seal blood vessels or tissue sheets. A typical instrument takes the form of a pair of opposing jaws or forceps, with one or more electrodes on each jaw tip. In an electrosurgical procedure, the electrodes are placed in close proximity to each other as the jaws are closed on a target site such that the path of alternating current between the two electrodes passes through tissue within the target site. The mechanical force exerted by the jaws and the electrical current combine to create the desired surgical effect. By controlling the level of mechanical and electrical parameters, such as the pressure applied by the jaws, the gap distance between electrodes, and the voltage, current, frequency, and duration of the electrosurgical energy applied to the tissue, the surgeon can coagulate, cauterize, or seal tissue toward a therapeutic end.
Electrosurgical procedures can be performed in an open environment, through conventional incisions, or they may be performed laparoscopically, through small incisions, typically 0.5 cm-1.5 cm in length. A laparoscopic procedure may include the use of a telescopic rod lens system that is connected to a video camera and to a fiber optic cable system that conveys light from a cold light source to illuminate the operative field. The laparoscope is typically inserted into a port in the body through a 5 mm or 10 mm cannula to view the operative field. Surgery is performed during a laparoscopic procedure with any of various tools that are typically arranged at the distal end of a shaft and are operable by manipulation of a handle or other actuator positioned at the proximal end of the shaft.
The laparoscopic operating environment is very constrained spatially; improvements with regard to the manipulatability of laparoscopic devices by surgeons, or more particularly, improvements in the range of motion that end effectors for electrosurgical device can achieve would be advantageous in the field.